1. Field of the Invention
The present invention generally relates to power-line networking and more particularly to a power supply with digital data coupling for power-line networking.
2. Description of the Related Art
There has recently been a growing interest in the use of power lines for high-speed data networking. For instance, the HomePlug(trademark) Powerline Alliance was formed to enable and promote the rapid availability and adoption of cost effective, interoperable and standards-based power-line home networks and products. To date, power-line networking technology delivering 14 Mbps networking speeds over residential (home) power lines has been demonstrated. With a high-speed power-line network, it is expected that virtually any electronic device found in the home may be networked through the power line.
For a power-line home network, direct current (DC) power in a computer system has been generated on an isolated or computer system side of a power supply, typically a switching power supply. Power-line network access circuitry such as a power-line analog front end (AFE), a digital-to-analog converter (DAC) and an analog-to-digital converter (ADC) has been driven by DC voltage from the system power. In order to drive a power line, a transformer has been necessary in the AFE for isolating the computer system side (isolated side) from the power line side (non-isolated side). Given the relatively low DC voltages typically used by integrated circuitry in the AFE on the isolated side, a transformer has also been necessary to achieve an adequate signal voltage level needed to drive a data carrier on a power line or power-line networking. However, the use of a transformer to amplify the power line data carrier increases the output impedance of the transmitter driver and introduces undesirable attenuation in the receive path. The isolated side typically provides DC voltages of +3.3 volts, +5 volts and +/xe2x88x9212 volts. With 3.3 volts, which is typical of most cost-effective AFE integrated circuitry, it would be very costly and difficult, if at all possible, to directly drive a data carrier into the power line with an adequate signal amplitude. As a result, an extra chip is required as a large signal amplifier driver having a larger power supply voltage of +/xe2x88x9212 volts to obtain adequate voltage swing to drive a data carrier onto the power line.
Briefly, a power supply provides digital data coupling for power-line networking. The power supply includes a power supply side digital interface to transmit and receive a digital data passed through a digital coupler to and from a power-line network access circuitry side digital interface of power-line network access circuitry. The power supply further includes a digital-to-analog converter to process digital data into a high-frequency analog data carrier to provide to a power line of a power-line network. An analog-to-digital converter of the power supply converts a high-frequency analog data carrier from the power line into digital data for the power-line network access circuitry. A power-line analog front end of the power supply transmits and receives the high-frequency analog data carrier to and from the power line. Digital data exchanged between the power supply and the network access circuitry may include control signals for a control circuitry of the power supply. Control circuitry of the power supply may handle control of the digital-to-analog converter, the analog-to-digital converter and the analog front end.